Propeller with selectively variable pitch



J. T. BYRD PROPELLER WITH SELECTIVELY VARIABLE PITCH March'3, 1964 2 Sheets-Sheet l INVENTOR.

TAMEs 7'." YRD Filed May 1. 1961 Ass/v1- March 3, 1964 J. T. BYRD PROPELLER WITH SELECTIVELY VARIABLE PITCH Filed May 1, 1961 2 Sheets-Sheet 2 AGENT United States Patent 3,123,145 PRQPELLER WITH SELECTIVELY VARIABLE PITCH James T. Byrd, Costa Mesa, Calif. (2636 55th Way, Apt. 6, Long Eeach, Calif.) Filed May 1, 1961, Ser. No. 106,779 Claims. (Cl. 17t)160.6)

This invention relates to propellers and is particularly concerned with marine propellers for use in driving boats and wherein safety and pitch selectivity are both required, it beirlg a general object of this invention to satisfy both of these requirements in a single and practical combination of elements.

The propeller of this invention is carried by and coupled to a propeller shaft, and the propeller hub not only mounts on said shaft with coupled engagement but the said hub also embodies features whereby selective adjustment of the blade pitch is made possible. The invention will be described in connection with boat or marine use; however, it will be readily apparent that the features herein disclosed are equally applicable to propellers designed for other use, or any equivalent s ructures.

In marine use, propellers are designed by diameter and pitch, in that a propeller is designated as having a certain diameter, say for example, fourteen inches diameter, and as having a certain pitch, say for example fifteen inches pitch. The pitch dimension indicates the lead or screw effect of the propeller for one revolution or turning thereof, and the pitch design of propellers varies widely in order to balance the propeller to the load imposed thereon by a prime mover used to move the particular boat involved. Ordinarily, resort has been made to trial and error methods in selecting propeller pitch, reliance being had on persons with sufficient experience to use good judgment. It therefore becomes apparent, without going into specific detail that there are many reasons for changing propeller pitch from time to time, or from boat to boat, or simply in experimentally selecting the proper pitch for a given installation. In any case, the usual method of exchanging propellers until a desirable pitch is found is costly and time consuming.

An object of this invention is to provide a propeller adapted to be coupled to a propeller shaft and adapted to be selectively varied in pitch. More specifically, the hub of the propeller is carried by the propeller shaft with driving engagement and the blades of the propeller are positionable as circumstances require.

It is a specific object of this invention to provide a propeller with a hub having a safety connection with the driving propeller shaft. In the propeller herein disclosed the hub is rotatably carried on the driving shaft, and a friction coupling affords normal driving engagement between the shaft and the hub.

It is a specific object of this invention to provide a propeller with selectively adjustable blades, whereby predetermined increments of blade pitch can be utilized throughout a Wide range of adjustment. In the propeller herein disclosed the blades are characterized by pivots that are rotatable relative to the hub and by adjustment means to position the said pivots rotatively whereby the blade pitch is established and set.

The various objects and features of this invention will be fully understood from the following detailed description of the typical preferred form and application thereof, throughout which description reference is made to the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view taken in a vertical plane through the central axis of a propeller embodying the features of the present invention. FIGS. 2 and 3 are sectional views taken as indicated by line 22 and 33 on FIG. 1. FIG. 4 is a horizontal sectional "ice View taken through the connection between the hub and propeller, as shown in FIG. 1, and FIG. 5 is a fragmentary enlargement of the features characterizing the said connection of the present invention.

In FIG. 1 of the drawings I have shown a typical twobladed propeller P carried on and driven by a propeller shaft S. The propeller P comprises, generally, a hub H carried by and rotatable on the shaft S about the axis a thereof, and by a plurality of blades B each extending radially from the hub H. It is to be understood that any number of blades can be employed, even one blade, the invention being characterized by a pivot A on each blade B and rotatably anchored in the hub H on a blade turning axis b. In the preferred form of the invention, the axis b is normal to and intersects the axis a. In accordance with the invention, a friction coupling C is provided to rotatably engage the shaft S and hub H, and an adjustment means D is provided to selectively position the blade B and its pivot A in the hub.

The propeller P is a combination of elements as related generally above, and it can be carried by any suitable shaft S to be driven by or to drive the same. As shown, the shaft S projects from a housing 1 3 on the axis a and has a shoulder 11 at the face 12 of the housing to engage and position the hub H. The shaft S is of substantial length and has a threaded end portion 13 to receive a retaining nut, there being a transverse opening 14 in the portion 13 to receive a shear pin.

The hub H is more or less cylindrical, having a rearwardly and inwardly tapered exterior wall 15. The hub H has front and rear end faces 16 and 17 that are spaced and parallel and normal to the axis a. There is a bore 18 that passes through the hub H and opening at the two faces 16 and 17, so that the hub H is free to rotate on the shaft S. The shoulder 11 engages the face 16 to position the hub and the face 17 is engaged by the friction coupling C, as later described. In accordance with the invention, the hub H has a socket 19 to receive the pivot A of the blade B. As shown, the socket 19 is a cylindrical bore on the axis b, and it opens laterally at the exterior Wall 15 of the hub so as to ro tatably receive the pivot A.

The hub H is retained in position on the shaft S by means of a nut 20 threaded onto the portion 13. A transverse opening 21 extends into the nut and such as to align with the opening 14 when the nut is properly positioned, and a shear pin 22 is confined to the openings 14 and 21 by a threaded plug 23 that closes the opening 21. The nut 26 has a front face 24 that opposes the face 17 in spaced parallel relationship.

In accordance with the invention I provide the friction coupling C which involves a clutch element held in pressured engagement with the two faces 24 and 17. The clutch element is preferably a single body of plastic material such as rubber or the like, which is de-formable so as to flow and which has a memory so as to return to its original state, substantially. In practice, the faces 7 and 24 are irregular in that the otherwise fiat surfaces thereof are redundant with a regular pattern of depressions 25. The said depressions 25 are semi-spherical dimples into which the body of rubber is depressiole. Molded dimples, or irregularities, can be provided on the body of rubber if so desired. As a result, a high degree of torque can be transmitted from the nut 2% to the hub H, with the safety feature of release under extreme and abnormal circumstances.

The blade B is formed integral with the pivot A, this part being cast of one body of material. The blade extends radially along the axis b and it is suitably shaped to have the most desirable propelling characteristics. The pivot A is a cylindrically-shaped part with a peripheral wall 26 adapted to enter and occupy the socket 19. The

3 point of joinder between the blade and pivot has an inwardly faced shoulder 27 engaged on an outwardly facing seat 28 at the wall 15.

In accordance with the invention, the adjustment means D is provided to selectively position the pivot A rotatably in the socket 19, and it involves a key 30 engageable in circumferentially spaced keyways 31 and 32 in the bore 19 and wall 26, respectively, with lock means 35 to secure the blade B in the selected position relative to the hub H. It will be apparent that the key 30 can vary widely in type and it is preferably a straight elongate body of square cross-section with fiat normal ends. In practice, the key 30 fully occupies the opening formed by two aligned keyways 31 and 32, each keyway being rectangular in cross-section with a fiat bottom and spaced parallel sides.

In carry ng out the invention, it is the circumferential spacing of the registering keyways 31 and 32 which results in selectively chooseable increments of positioning. Generally, the keyways 31 are spaced differently than the keyways 32, and said spacing can be varied in either case. In the particular case under consideration, it is desired to have even increments of rotational adjnstment,, 2-15 per increment. Therefore, the keyways are each evenly spaced. the keyways 31 being apart 2- farther per increment than the spacing of the keyways 32. As shown, the keyways 31 are spaced 51 apart circumferentially, and keyways 32 are spaced 48- 45 apart circumferentially. Thus, by removing the key and by revolving the pivot A 2-15 at a time, the said pivot can be advanced or retracted rotatably from any previously selected position, and the key 30 reinstalled in the next circumferentially adjacent opening formed by the aligned keyways 31 and 32.

In FIG. 4 of the drawings I have shown dimensionally the particular example disclosed above and wherein increments of 2-15' alter the blade pitch approximately one inch per increment of adjustment. The parts are shown at a selected adjustment of 15 inch pitch, at which position all other opposed keyways 31 and 32 are out of alignment, as clearly illustrated.

From the foregoing it will be apparent that a relatively fine adjustment can be made in increments of 2-15', or coarser or finer, if so desired. In any case, when said adjustment is made, With the hub H removed from the shaft S, the lock means is operable to secure the pivot A in the selected position. As shown, I provide a conepointed set screw 36 operable into pressured engagement with an upwardly disposed face 37 on the pivot A. In

practice, the face 37 is formed by a V-shaped groove in the wall 26, disposed horizontally and adapted to trans fer lateral pressure from the set screw and to force the shoulder 27 into seated engagement with the seat 28. The key 30 is confined in operative position by the assemly of parts, as shown. Further, I provide substantially diametrically opposite lock 35 means threaded into the hub and locking the pivot A in the selected position. Further, it will be apparent that right and left handed blades can :be readily and conveniently exchanged, one for the other, damaged blades can be replaced, and blades of various design configurations can be selected and used, all as circumstances require.

Having described only a typical preferred form and application of my invention, I do not Wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any modifications or variations that may appear to those skilled in the art fall within the scope of following claims.

Having described my invention, I claim:

1. A propeller carried by a shaft and including a hub part drivingly engaged with the shaft and having a laterally disposed socket therein, a radially extending blade part with an inwardly projecting pivot rotatable in said socket, and means incrementally positioning the pivot rotatively in said socket and comprising a key occupying a pair of opposed keyways in the socket and pivot respectively, there being a plurality of circumferentially spaced keyways in both the socket and the pivot, the said circumferential spacing being greater in one part than the other, whereby the blade is selectively positionable.

2. A propeller carried by a shaft and including, a hub part drivingly engaged with the shaft and having a laterally disposed socket therein, a radially extending blade part with an inwardly projecting pivot rotatable in said socket, and means incrementally positioning the pivot rotatively in said socket and comprising a key occupying a pair of opposed keyways in the socket and pivot respectively, there being a plurality of circumferentially spaced keyways in both the socket and the pivot, the said keyways being spaced differently in the socket than in the pivot, whereby the blade is selectively positionable:

3. A propeller carried by a shaft and including,ia hub part drivingly engaged with the shaft and having a laterally disposed socket therein, a radially extending blade part with an inwardly projecting pivot rotatable in said socket, and means incrementally positioning the pivot ro tatively in said socket and comprising a key occupying a pair of opposed keyways in the socket and pivot respectively, there being a plurality of circumferentially spaced keyways in both the socket and the pivot, the said keyways being uniformly spaced in both of said parts, and said spacing being greater in one part than the other, whereby the blade is selectively positionable.

4. A propeller carried by a shaft and including, a hub part drivingly engaged with the shaft and having a laterally disposed socket therein, a radially extending blade part with an inwardly projecting pivot rotatable in said socket, means incrementally positioning the pivot rota tively in said socket and comprising a key occupying a pair of opposed keyways in the socket and pivot respectively, there being a plurality of circumferentially spaced keyways in both the socket and the pivot, the said keyways being spaced differently in the socket than in the pivot, whereby the blade is selectively positionable, and lock means holding the pivot in the selected position.

5. A propeller carried by a shaft and including, a hub part drivingly engaged with the shaft and having a later ally disposed socket therein, a radially extending blade part with an inwardly projecting pivot rotatable in said socket, means incrementally positioning the pivot rotatively in said socket and comprising a key occupying a pair of opposed keyways in the socket and pivot respectively, there being a plurality of circumferentially spaced keyways in both the socket and the pivot, the said circumferential keyway spacing being greater in one part than the other, whereby the blade is selectively positionable, and lock means holding the pivot in the selected position.

References tilted in the file of this patent UNlTED STATES PATENTS 787,084 Donnelly Apr. 11, 1905 794,010 Hayden July 4, 1905 945,663 Yeager Jan. 4, 1910' 1,769,801 McCauley July 1, 1930 2,164,485 Yantis July 4, 1939 2,228,524 Lampton Ian. 14, 1941 2,564,605 Martin Aug. 14, 1951 2,605,850 Kiekhaefer Aug. 5, 1952 2,633,923 Hartz Apr. 7, 1953 2,642,730 Snyder June 23, 1953 2,653,459 Morrill Sept. 29, 1953 2,772,586 Jones Dec. 4, 1956 2,773,365 Delf Dec. 11, 1956 3,077,228 Mohn Feb. 12, 1963 FOREIGN PATENTS 27,417 Finland May 14, 1955 171,057 Great Britain Nov. 10, 1921 367,265 Great Britain Feb- 18, 1932 

